Safe and reliable water supply

The Christchurch water supply system is based on a system of wells dispersed across the city with the water being distributed to residents through pumping stations and approximately 3000 kilometers of pipe.

Water supplies meet the public's reasonable needs

The groundwater sources that supply Christchurch are expected to reach indicative abstraction limits in the mid-twenty-first century. Surface water sources that supply Akaroa Harbour are already under seasonal demand pressure. This, along with increasing demand for water resources, could have long term impacts on water supply.

Key Points

In 2016, over 90% of residents were satisfied with the quality of water supply. This is the first time post-earthquake that resident satisfaction of water supply has exceeded 90%.

The water supply network is very reliable with around 16 unplanned interruptions per 1,000 properties. This is slightly higher than pre-earthquake when it was around 12 per 1,000 properties.

The delivery of water to properties is very reliable with around 16 unplanned interruptions per 1,000 properties. This is slightly higher than pre-earthquake when it was around 12 per 1,000 properties.

97% of urgent leaks in 2015 were responded to within 2 hours. This is a similar level to pre-earthquake response rates.

Over 90% of medium and minor leaks area were repaired within 1 and 3 working days respectively. This is almost as good as pre-earthquake when over 97% met these timeframes.

Time Taken to Repair Water Leaks

More detail and information

CCC Infrastructure Strategy:(external link) The purpose of Council’s Infrastructure Strategy is to identify significant infrastructure issues for the local authority over the next 30 years and to identify the principal options for managing those issues and the implications of those options.

Clean, safe drinking water

The aquifers on the western side of the city supply most of urban Christchurch and Lyttelton Harbour's drinking water. They are semi confined or unconfined aquifers characterised with thin, permeable soils underlain by gravels. These soils provide little protection against contaminants which can migrate into groundwater.

Key points

Ministry of Health 2016 water grading indicated around 72% of Christchurch residents were connected to a water supply graded “Ba”. However, 85,000 people live in the north-west zone with a water supply graded “Da”. The 'D' grade means there is an unacceptable level of risk of contamination at the water source or during treatment; the "a' means there is an extremely low level of risk of contamination occurring to water in the reticulation network.

Water supplies for rural settlements on Banks Peninsula (excluding Lyttelton Harbour basin) are currently ungraded (Uu).

The city’s urban water supplies meet Drinking Water Standards NZ bacterial and protozoal criteria. The proportion of rural residents connected to a supply compliant with bacterial criteria has risen from 67% in 2010 to 100% in 2015. The proportion of rural residents supplied with water compliant with protozoal criteria has remained constant at 11% .

Bacterial Compliance of Drinking Water Quality

Urban and Rural Water Quality

Source: Council Levels of Service Reporting

Population Per Water Supply Grading

Source: Statistics NZ & MoH

More detail and information

Drinking Water for New Zealand:(external link)In order to compare water supplies and identify those which may not be delivering quality water, the Ministry of Health grades each supply. So far, only those with populations over 500 are graded, but those with as few as 25 users will be graded in the future

Water Supply Strategy: Christchurch water is currently of a very high quality, but intensified land-use and new development may increase the risk of groundwater contamination.